Insulated support for electric conductors.



Patented Nov. 27, I900.

C. C. BLAKE.

INSULATED SUPPORT FOR ELECTRIC CONDUCTOBS.

(Applination filed May 18, 1000.

(No Model.)

4 JNVENTOR. M 6, m l Ad BY A ATTORNEY.

W QQJQEZ UNITED STATES PATENT OEEIcE.

CHARLES CHANDLER BLAKE, OF PORTSMOUTH, NEW HAMPSHIRE.

INSULATED SUPPORT FOR ELECTRIC CONDUCTOR S.

SPECIFICATION forming part of Letters Patent No. 662,587, dated November27, 1900.

Application filed May 18,1900. Serial No. 17,136. (No model.)

To all whom, it may concern:

Be it known that I, CHARLES CHANDLER BLAKE, residing at Portsmouth, inthe State of New Hampshire, have invented certain Improvements inInsulated Supports for Electric Conductors, of which the following is aspecification.

The present invention relates to insulating means for supportingelectric conductors on a wall or other surface; and it consists of adouble-pointed metal staple provided with an insulating-lining for itsinner upper surface and sides, secured to the prongs of the staple byfrictional pressure.

Formerly conductors were held to supports by bare double tacks orstaples; but it was found that when driven in too far the insulation ofthe conductor was often cut, so that a short circuit was made when twoor more conductors were under one staple or a ground was introduced whenone conductor was under the same. Consequently it became the practice towind tape around the conductor where the staple was to be driven tofurther protect the same, or the upper part of the staple was protectedby a winding of tape, or a piece of tape was introduced between theconductor and the head of the staple. There have been in use variouskinds of devices for the further protection of the conductor. Forinstance, there has been furnished the trade a button of some insulatingmaterial of a general cylindrical form with tapered, conical, or squaredends, one side of which is cut away or made fiat, with a cavityextending in from the flat side the entire length of the button toreceive the wire. A channel or groove is made in the cylindricalexterior portion of the button midway its length, which is adapted toreceive the staple, and when the device is to be secured over aconductor a special tool is used which fits the curved top of the stapleand blows are applied to its end. The insulating-button is secured tothe inner end of the staple by frictional pressure. In other words,itwas forced thereinto. Other means for supporting conductors onsurfaces are in use, such as a stout metal staple provided withshoulders at the springing of the inner curve of the head, combined witha short piece of thin insulating material just long enough so that itsends will be braced between the opposite shoulders, while its body ispressed against the said inner curve. To assist the insulatingpiece tobe retained in position, it is cement ed to the staple, or a coat ofjapan is applied to the staple and the said piece, which forms a thinuniting-covering. All of the devices that I have mentioned aredefective, as the insulaiing-l'mtton of one will not stayin place, andthe insnlating-pieces of another become detached when shaken up withothers in the containing-package furnished the trade; but moreespecially do they prove defective, even while the insulating buttonsand pieces remain in position, when the staple is driven into thesupport, as in all the devices I have mentioned or am aware of thestaples are made with half-round heads, and when driven into moderatelyhard wood the heads are flattened and distorted, so much so that thebuttons and pieces do not remain in place and frequently are forced outaltogether before the head of the staple reaches the conductor. Thepresent invention aims to avoid these troubles and failures and consistsin the following means.

Of the drawings Figures 1, 2, and 3 illustrate the invention, beingrespectively a side and end view of the device assembled and of theinsulation-strip developed or spread out, while by Figs. 4, 5, 6, 7, S,and 9 I have endeavored to illustrate the features in devices of thischaracter which I aim to avoid. Figs. 1, 2, and 3 are three timesnaturalsize, and the remaining figures are twice natural size. Figs. 4and 5 are side views of staples a with halfround heads. I) isaninsulated conductor,and 19 a piece of insulation through which theprongs of the staple are pressed, this being an ordinary means used. Thelatter figure shows how the round head becomes distorted when the stapleis driven into hard wood, and the prongs of the staple do not affordadequate support to the conductor. Figs. 6 and 7 represent a side andedge view of a device consisting of a round-headed staple and aninsulating-button adapted to surround a wire,-

the button having a groove in its top for the reception of thestaple-head. The button is supported by friction, it being forced intoplace. When driven in by a special tool fitting the curved head, thereis no crippling of the head; but when the hammeris applied to the headthe same will be distorted, as shown by Fig. 5. Figs. 8 and 9 show astout staple, With shoulders fat the springing of the circle of thehead, and b is a piece of insulation just long enough so that its endsare supported by the shoulders, while its surface is pressed to theinner part of the head. Fig. 9 shows the effect of driving the staplewith ahammerintohard wood. The head becomes distorted, as also does theinsulation Z2 and the latter frequently flies out altogether.

In carrying out my invention I provide a staple with a substantiallyflat head, the curves at the upper corners being very short and abrupt,and it may be any of the suitable staples provided to the trade. Theinsulation is made of comparatively long narrow and thin strips of anysuitable insulating material, such as the ordinary tan-colored fiber. Atproper distances from each end two slits c and c are cut through thesame. The ends are then brought to the center to form a loop and toucheach other, and the prongs of the staple are forced through the slits aa into the space between the two end loops and then out through theslits c 0 and the middle of the insulation presses against the innersurface of the staple-head as a cushion, as shown in the figures. Thisis done when the strip 1) is moist and flexible, and when it becomes dryand resilient the slits a and 0 close tightly upon the surfaces of theprongs, and the strip is only removed by the application of considerable force.

1' have only roughly indicated how the strip is strung upon the staple,as practically the operation is performed by a machine.

It will be seen that by this construction very efficient protection isfurnished to even a bare conductor, as when applied to one of the properdiameter the end loops of insulation extend over not only the sides tothe faces of the support into which the staple is driven, but over thetop also, with a double thickness, while the outer or end flat surfaceof the staple is left bare to receive the blows of a hammer, which donot distort the staple nor dislodge the insulation.

I claim as my invention 1. An insulating device forsupportingconductors, consisting of a staple with a flat head; with aninsulating-strip covering the inner and outer surfaces of the upper partof the prongs with one thickness and the inner surface of the head withtwo thicknesses, the same being held to the surfaces of the staple byfrictional pressure. 7

2. An insulating device forsupporting cond uctors, consisting of astaplewith a fiat head; with an insulating-strip covering the inner and outersurfaces of the upper part of the prongs with one thickness and theinner surface of the head with two thicknesses all of which project fromeach side of the said staple, the same being held to the surfaces of thestaple by frictional pressure.

3. Means forsupporting electric conductors consisting of adouble-pointed tack or staple having a substantially flat head, with aninsulating-cushion composed of a comparatively long narrow and thinstrip bent into a loop, and having four perforations or slits, each ofthe prongs of the staple projecting through two of said slits, thecenter and the two ends of the strip meeting under the head of thestaple, as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 15th day of May, 1900.

CHAS. CHANDLER BLAKE.

Witnesses:

GEO. WILLIs PIERCE, J OSEPH A. GATELY.

